What should be used to tone skin after removing a facial mask?

Using a mild astringent is the appropriate choice for toning skin after removing a facial mask because it helps to restore the skin's pH balance, close the pores, and prepare the skin for subsequent products like moisturizers or serums. Mild astringents typically contain beneficial ingredients that can soothe and refresh the skin, which is important after the potentially drying effects of a facial mask.

In contrast, sugar is an exfoliant rather than a toning agent, and it could irritate the skin post-treatment. Uric acid, while used in certain dermatological contexts, is not standard for skin toning and could cause irritation. A strong disinfectant is inappropriate for use on the skin after a facial, as it can be overly harsh and damaging, potentially leading to dryness or irritation instead of the calming effect desired in a post-mask routine.